Welcome, a couple have sold on here.
This should help you:
http://www.retrobike.co.uk/forum/viewtopic.php?t=202267&highlight=kona+stab
This should help you:
http://www.retrobike.co.uk/forum/viewtopic.php?t=202267&highlight=kona+stab
cyfa2809":36o0lt4o said:I estimate about £110 for the zaskar frame.